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52-582: A popular river for whitewater canoeing enthusiasts, it is often grouped together with the Dumoine and Noire Rivers as three of a kind. The three rivers share the same watershed, and have similar whitewater characteristics. All three empty into the Ottawa River within a distance of 105 kilometers (65 mi) from one another. One of a dozen or so significant tributaries of the Ottawa River ,

104-685: A river 's gradient changes enough to generate so much turbulence that air is trapped within the water. This forms an unstable current that froths , making the water appear opaque and white. The term "whitewater" also has a broader meaning, applying to any river or creek that has a significant number of rapids. The term is also used as an adjective describing boating on such rivers, such as whitewater canoeing or whitewater kayaking . Four factors, separately or in combination, can create rapids: gradient, constriction, obstruction, and flow rate. Gradient, constriction, and obstruction are streambed topography factors and are relatively consistent. Flow rate

156-653: A French explorer who spent the winter of 1694–95 at the nearby Allumettes Island . The Coulonge was used as a waterway by native North Americans and, later, by the coureurs des bois plying their independent trade in furs . In 1784, the North West Company built a fort at the mouth of the river, named Fort Coulonge, which passed into the hands of the Hudson's Bay Company when the two companies merged in 1821. In 1835, Scottish-born lumber baron George Bryson acquired timber rights to thousands of acres of forest in

208-467: A boatsman with passengers having no direct responsibilities. Catarafts can be of all sizes; many are smaller and more maneuverable than a typical raft. Canoes are often made of fiberglass, kevlar, plastic, or a combination of the three for strength and durability. They may have a spraycover , resembling a kayak, or be "open", resembling the typical canoe. This type of canoe is usually referred to simply as an "open boat". Whitewater canoes are paddled in

260-455: A bucket, and because the only way to get water out of them is by bailing with a bucket. Catarafts are constructed from the same materials as rafts. They can either be paddled or rowed with oars. Typical catarafts are constructed from two inflatable pontoons on either side of the craft that are bridged by a frame. Oar-propelled catarafts have the occupants sitting on seats mounted on the frame. Virtually all oar-powered catarafts are operated by

312-413: A canoe. C1s are similar in construction to whitewater kayaks, but they are paddled in a low, kneeling position. They employ the use of a one-blade paddle, usually a little shorter than used in a more traditional canoe. They have a spraycover, essentially the same type used in kayaking. Like kayaks, C1s can be righted after capsizing with an Eskimo roll. McKenzie River dory (or "drift boat" by some)

364-597: A height of 48 meters (157 ft), is approximately 15 kilometers (9.3 mi) upstream of the confluence with the Ottawa River. The historic Félix-Gabriel-Marchand Bridge crosses the Coulonge River near Fort-Coulonge. Constructed in 1898, this 148.66 metres (487.7 ft) long bridge is the longest covered bridge in Quebec. Over the period 1926 to 1993, the Coulonge River had a mean flow of 74.1 cubic metres per second (2,620 cu ft/s). Mean minimal flow

416-493: A low kneeling position, with a one-bladed paddle. Open whitewater canoes often have large airbags and in some cases foam, usually 2-lb density ethyl foam, firmly attached to the sides, to displace water in the boat when swamped by big waves and holes and to allow water to be spilled from the boat while still in the river by floating it up on its side using the foam and bags. Like kayaks, whitewater canoes can be righted after capsizing with an Eskimo roll, but this requires more skill in

468-424: A lower rated rapid may give a better "ride" to kayakers or rafters, while a Class V may seem relatively tame. However, it is not so much the "ride," but the inherent danger in the rapid. An exiting rapid may have minimal risk, while a seemingly simply rapid may have terminal hydraulics, undercut rocks, etc.) A rapid's grade is not fixed, since it may vary greatly depending on the water depth and speed of flow. Also,

520-440: A rapid to be created. Rapids are hydrological features between a run (a smoothly flowing part of a stream ) and a cascade. Rapids are characterized by the river becoming shallower with some rocks exposed above the flow surface. As flowing water splashes over and around the rocks, air bubbles become mixed in with it and portions of the surface acquire a white color, forming what is called " whitewater ". Rapids occur where

572-628: A river has a larger gradient, the water flows downhill faster. Gradients are typically measured in feet per mile. This impacts the river's flow or discharge , which is measured as a volume of water per unit of time. The faster the water flows, the more likely a rapid will form. Rapids are categorized in classes , generally running from I to VI. A Class 5 rapid may be categorized as Class 5.1-5.9. While Class I rapids are easy to navigate and require little maneuvering, Class VI rapids pose threat to life with little or no chance for rescue. River rafting sports are carried out where many rapids are present in

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624-485: A river is the rate at which it changes elevation along its course. This loss determines the river's slope, and to a large extent its rate of flow (velocity). Shallow gradients produce gentle, slow rivers, while steep gradients are associated with raging torrents. Constrictions can form a rapid when a river's flow is forced into a narrower channel. This pressure causes the water to flow more rapidly and to react to riverbed events (rocks, drops, etc.). A boulder or ledge in

676-612: A steep canyon, the side walls of the canyon can also be undercut. A particularly notorious undercut rock is Dimple Rock, in Dimple Rapid on the Lower Youghiogheny River , a very popular rafting and kayaking river in Pennsylvania. Of about nine people who have died at or near Dimple Rock, including three in 2000, several of the deaths were the result of people becoming entrapped after they were swept under

728-418: A strong sideways or diagonal (also called a "lateral") wave can throw the craft off if the craft hits sideways or at an angle. The safest move for a whitewater boater approaching a lateral is to "square up" or turn the boat such that it hits the wave along the boat's longest axis, reducing the chance of the boat flipping or capsizing. This is often counterintuitive because it requires turning the boat such that it

780-486: A surfer slipping out the end of the pipeline, where the wave no longer breaks. Low-head dams are insidiously dangerous because their danger cannot be easily recognized by people who have not studied swift water. (Even 'experts' have died in them.) Floating debris (trees, kayaks, etc.) is often trapped in these retroflow 'grinders' for weeks at a time. Waves are formed in a similar manner to hydraulics and are sometimes also considered hydraulics, as well. Waves are noted by

832-438: Is a more traditional "hard sided" boat. The design is characterized by a wide, flat bottom, flared sides, a narrow, flat bow, a pointed stern, and extreme rocker in the bow and stern to allow the boat to spin about its center for ease in maneuvering in rapids. River bugs are small, single-person, inflatable craft where a person's feet stick out of one end. River bugging is done feet first with no paddle. Creature Craft are

884-513: Is a short list of them: Whitewater kayaks differ from sea kayaks and recreational kayaks in that they are better specialized to deal with moving water. They are often shorter and more maneuverable than sea kayaks and are specially designed to deal with water flowing up onto their decks. Most whitewater kayaks are made of plastics now, although some paddlers (especially racers and "squirt boaters") use kayaks made of fiberglass composites. Whitewater kayaks are fairly stable in turbulent water, once

936-450: Is dependent upon both seasonal variation in precipitation and snowmelt and upon release rates of upstream dams. Streambed topography is the primary factor in creating rapids, and is generally consistent over time. Increased flow, as during a flood or high-rainfall season, can make permanent changes to the streambed by displacing rocks and boulders, by deposition of alluvium , or by creating new channels for flowing water. The gradient of

988-402: Is no longer parallel to the current. In fluid mechanics, waves are classified as laminar, but the whitewater world has also included waves with turbulence ("breaking waves") under the general heading of waves. Pillows are formed when a large flow of water runs into a large obstruction, causing water to "pile up" or "boil" against the face of the obstruction. Pillows normally signal that a rock

1040-581: Is not undercut. Pillows are also known as "pressure waves". Eddies are formed, like hydraulics, on the downstream face of an obstruction. Unlike hydraulics, which swirl vertically in the water column, eddies revolve on the horizontal surface of the water. Typically, they are calm spots where the downward movement of water is partially or fully arrested—a place to rest or to make one's way upstream. However, in very powerful water, eddies can have powerful, swirling currents that trap or even can flip boats and from which escape can be very difficult. Located between

1092-491: Is the International Scale of River Difficulty , where whitewater (either an individual rapid, or the entire river) is classed in six categories from class I (the easiest and safest) to class VI (the most difficult and most dangerous). The grade reflects both the technical difficulty and the danger associated with a rapid, with grade I referring to flat or slow-moving water with few hazards, and grade VI referring to

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1144-608: Is used than on flat water. Running whitewater rivers is a popular recreational sport, but is not without danger. Fast-moving water always has the potential for injury or death by drowning or hitting objects. Fatalities do occur; some 50 people die in whitewater accidents in the United States each year. The dangers can be mitigated (but not eliminated) by training, experience, scouting, the use of safety equipment (such as personal flotation devices , helmets, throw ropes), and using other persons as "spotters". Scouting or examining

1196-436: The bed material is highly resistant to the erosive power of the stream in comparison with the bed downstream of the rapids. Very young streams flowing across solid rock may be rapids for much of their length. Rapids cause water aeration of the stream or river, resulting in better water quality. For a rapid to form, a necessary condition is the presence of a gradient, which refers to the river or stream's downward slope. When

1248-609: The 20th. The last spring log drive in Canada took place on the Coulonge River in 1982. Since then, the timber from smaller-scale logging operations has been hauled out by trucks over a network of dirt roads which meander throughout the Coulonge River valley. In 1994, a hydro-electric dam and power station was built at the head of the Grandes Chutes, leaving the Dumoine River as the last major free-flowing tributary of

1300-568: The American version of the International Scale of River Difficulty). On any given rapid, a multitude of different features can arise from the interplay between the shape of the riverbed and the velocity of the water in the stream. Strainers are formed when an object blocks the passage of larger objects, but allows the flow of water to continue – like a big food strainer or colander . These objects can be very dangerous, because

1352-553: The Coulonge River has a length of 240 kilometres (150 mi) and a drainage area of 5,060 square kilometres (1,950 sq mi), and runs in a general south-eastern direction from its headwaters in Lac au Barrage (situated in La Vérendrye Wildlife Reserve ) to the Ottawa River at Fort-Coulonge . Over that distance, it drops approximately 260 meters (850 ft). The massive Grandes or Coulonge Chutes , with

1404-423: The Ottawa River. In August 2020, 2 persons drowned in the Coulonge River in separate incidents: the body of a woman was found just north of Fort Coulonge; and a man was swept away by strong rapids while swimming about 40 kilometres (25 mi) upstream. [REDACTED] Media related to Rivière Coulonge at Wikimedia Commons Whitewater Whitewater forms in the context of rapids , in particular, when

1456-452: The area, including the 200 acres (81 ha) immediately surrounding the Grandes Chutes. In 1843, Bryson built a sawmill near the mouth of the river, which led to permanent settlement and the formation of the village of Fort-Coulonge . To transport the squared timber safely past the falls and the 750 m (2,460 ft) gorge below, Bryson built a 915 m (3,002 ft)-long timber slide (a wooden chute flowing with water diverted from

1508-423: The course. Constriction refers to when rivers flow through narrower channels, thus increasing the velocity of the water. This may also lead to the creation of obstructions due to sediment transportation and erosion . Obstacles may occur by human activity, natural landslides and earthquakes, or accumulation of sediment or debris. The more prominent these four factors are present in a river, the more likely that river

1560-576: The eddy and the main current, the eddy line is a swirling seam of green and sometimes white water. Eddy lines vary in size based on the size of the water column, the gradient of the section, and the obstacle creating the eddy. Often containing boils and whirlpools, eddy lines can spin and grab your watercraft in unexpected ways, but if used correctly, they can be a really playful spot. Full slice and half slice boaters are able to perform tricks like stern squirts and cartwheels, but nobody uses eddy lines as well as squirt boaters(link to squirt boating wiki), who use

1612-402: The flow rate. In large rivers with high flow rates next to an obstruction, "eddy walls" can occur. An eddy wall is formed when the height of the river is substantially higher than the level of the water in the eddy behind the obstruction. This can make it difficult for a boater, who has stopped in that particular eddy, to re-enter the river due to a wall of water that can be several feet high at

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1664-406: The force of the water will pin an object or body against the strainer and then pile up, pushing it down under water. For a person caught in this position, getting to safety will be difficult or impossible, often leading to a fatal outcome. Strainers are formed by many natural or man-made objects, such as storm grates over tunnels, trees that have fallen into a river ("log jam"), bushes by the side of

1716-407: The hardest rapids, which are very dangerous even for expert paddlers, and are rarely run. Grade-VI rapids are sometimes downgraded to grade-V or V+ if they have been run successfully. Harder rapids (for example a grade-V rapid on a mainly grade-III river) are often portaged , a French term for carrying. A portaged rapid is where the boater lands and carries the boat around the hazard. (In many cases,

1768-517: The head of the falls), which was replaced by a concrete chute in 1923. For almost 150 years, the forests around the Coulonge were logged throughout the winter months until spring breakup permitted the massive log drives which, along with similar operations throughout the Ottawa River watershed, fueled the economy of the Ottawa Valley region from the early 19th century through the middle of

1820-443: The large, smooth face on the water rushing down. Sometimes, a particularly large wave also is followed by a "wave train", a long series of waves. These standing waves can be smooth, or particularly the larger ones, can be breaking waves (also called "whitecaps" or "haystacks"). Because of the rough and random pattern of a riverbed, waves are often not perpendicular to the river's current. This makes them challenging for boaters, since

1872-516: The level of development in rafting/kayaking technology plays a role. Rapids that would have meant almost certain death a hundred years ago may now be considered only a Class IV or V rapid, due to the development of certain safety features. Although some rapids may be easier at high flows because features are covered or "washed-out", high water usually makes rapids more difficult and dangerous. At flood stage, even rapids that are usually easy can contain lethal and unpredictable hazards (briefly adapted from

1924-481: The middle of a river or near the side can obstruct the flow of the river, and can also create a "pillow"; when water flows backwards upstream of the obstruction, or a "pour over" (over the boulder); and "hydraulics" or "holes" where the river flows back on itself—perhaps back under the drop—often with fearful results for those caught in its grasp. (Holes, or hydraulics, are so-called because their foamy, aerated water provides less buoyancy and can feel like an actual hole in

1976-472: The most dangerous types of holes are formed by low-head dams ( weirs ), and similar types of obstructions. In a low-head dam, the 'hole' has a very wide, uniform structure with no escape point, and the sides of the hydraulic (ends of the dam) are often blocked by a man-made wall, making paddling around, or slipping off, the side of the hydraulic, where the bypass water flow would become normal (laminar), difficult. By (upside-down) analogy, this would be much like

2028-435: The object under the water. In a river, swimming aggressively away from the strainer and into the main channel is recommended. If avoiding the strainer is not possible, one should swim hard towards it and try to get as much of one's body up and over it as possible. Sweepers are trees fallen in or heavily leaning over the river, still rooted on the shore and not fully submerged. Their trunks and branches may form an obstruction in

2080-402: The object. Holes can be particularly dangerous—a boater or watercraft may become stuck under the surface in the recirculating water—or entertaining play-spots, where paddlers use the holes' features to perform various playboating moves. In high-volume water flows, holes can subtly aerate the water, enough to allow craft to fall through the aerated water to the bottom of a deep 'hole'. Some of

2132-705: The paddler is skillful with them; if flipped upside-down, the skilled paddler can easily roll them back upright. This essential skill of whitewater kayaking is called the " Eskimo roll ", or simply "roll". Kayaks are paddled in a low sitting position (legs extended forward), with a two-bladed paddle. See Whitewater kayaking . Rafts are also often used as a whitewater craft; more stable than typical kayaks, they are less maneuverable. Rafts can carry large loads, so they are often used for expeditions. Typical whitewater rafts are inflatable craft, made from high-strength fabric coated with PVC, urethane, neoprene or Hypalon; see rafting . While most rafts are large multipassenger craft,

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2184-433: The point at which the eddy meets the river flow. A marked increase or decrease in flow can create a rapid, "wash out" a rapid (decreasing the hazard), or make safe passage through previously navigable rapids more difficult or impossible. Flow rate is measured in volume per unit of time. The stream flow rate may be faster for different parts of a river, such as if there's an undercurrent. The most widely used grading system

2236-489: The rapids before running them is crucial to familiarize oneself with the stream and anticipate the challenges. This is especially important during flood conditions when the highly increased flows have altered the normal conditions drastically. Rapids Rapids are sections of a river where the river bed has a relatively steep gradient , causing an increase in water velocity and turbulence . Flow, gradient, constriction, and obstacles are four factors that are needed for

2288-440: The river like strainers. Since it is an obstruction from above, it often does not contribute to whitewater features, but may create turbulence. In fast water, sweepers can pose a serious hazard to paddlers. Holes, or " hydraulics ", (also known as "stoppers" or "souse-holes" (see also Pillows ) are formed when water pours over the top of a submerged object, or underwater ledges, causing the surface water to flow back upstream toward

2340-411: The river surface.) If the flow passes next to the obstruction, an eddy may form behind the obstruction; although eddies are typically sheltered areas where boaters can stop to rest, scout, or leave the main current, they may be swirling and whirlpool-like. As with hydraulics (which pull downward rather than to the side and are essentially eddies turned at a 90° angle), the power of eddies increases with

2392-417: The river that are flooded during high water, wire fence, rebar from broken concrete structures in the water, or other debris. Strainers occur naturally most often on the outside curves of rivers where the current undermines the shore, exposing the roots of trees and causing them to fall into the river and form strainers. In an emergency, climbing on top of a strainer may be better so as not to be pinned against

2444-413: The rock. Another major whitewater feature is a sieve, which is a narrow, empty space through which water flows between two obstructions, usually rocks. Similar to strainers, water is forced through the sieve, resulting in higher velocity flow, which forces water up and creates turbulence. People use many types of whitewater craft to make their way down a rapid, preferably with finesse and control. Here

2496-489: The smallest rafts are single-person whitewater craft, see packraft . Rafts sometimes have inflatable floors, with holes around the edges, that allow water that splashes into the boat to easily flow to the side and out the bottom (these are typically called "self-bailers" because the occupants do not have to "bail" water out with a bucket). Others have simple fabric floors, without anyway for water to escape, these are called "bucket boats", both for their tendency to hold water like

2548-412: The swirling water and crossing currents to dance below the surface of the river. Undercut rocks have been worn down underneath the surface by the river, or are loose boulders which cantilever out beyond their resting spots on the riverbed. They can be extremely dangerous features of a rapid because a person can get trapped underneath them under water. This is especially true of rocks that are undercut on

2600-579: The ultimate whitewater craft, with a roll cage design that protects the occupants if they are to flip in any manner. You can see these creatures drifting down rivers like the Gauley, waiting to be capsized and righted by other enthusiastic river users. Whitewater SUP (Stand Up Paddle Boarding) , similar to traditional flat water stand up paddle boarding, whitewater SUPing involves the use of a stand up paddle board to run whitewater. The boards are typically specially designed for whitewater use, and more safety gear

2652-433: The upstream side. Here, a boater may become pinned against the rock under water. Many whitewater deaths have occurred in this fashion. Undercuts sometimes have pillows, but other times the water just flows smoothly under them, which can indicate that the rock is undercut. Undercuts are most common in rivers where the riverbed cuts through sedimentary rocks such as limestone rather than igneous rock such as granite . In

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2704-534: Was 25.1 cubic metres per second (890 cu ft/s) and mean maximum flow was 195 cubic metres per second (6,900 cu ft/s). Record maximum flow was 410 cubic metres per second (14,000 cu ft/s) in May 1947, while record minimum flow was 9.58 cubic metres per second (338 cu ft/s) in October 1948. The Coulonge River is named after Nicholas d'Ailleboust de Manthet (1663–1709), Sieur de Coulonge,

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